Some homebrew amps do perform as well if not better than the high end manufacturers products. But in my experience many fall short, often without the builders being aware. No I do not make them aware if the short commings as a rule, I sometimes suggest improvements though:)
Where do you think that DIY amps most often fail to perform better than they could, or where should we be concentrating more effort?

I'd be greatfull for you experience.

Enjoy the music, take care, regards, WALKER

MikeW

15th June 2003 01:58 PM

I think the biggest problem for the DIY is the housing and hardware. Except for Peter. Heatsink are always hard to get. The electronics are the easy part. There are alot of good proven designs to build thanks to Nelson Pass, Rod Elliott, Hugh Dean just to mention a few.

walker

15th June 2003 02:14 PM

Chassis and heatsinking

How much do the chassis and heatsinks effect the performance?
Certainly a poor enclosure can cause shielding and grounding problems.
The heatsinks apart from size, how else do you think that they effect the output?

Take care, enjoy the music, regards WALKER

Jean

15th June 2003 07:59 PM

I agree with MikeW, and would like to add physical layout and relative location of psu components to the list too. Thats just from my personal experience of course :)

dutch diy

15th June 2003 09:11 PM

Probably each DIY at some point bends one or two rules related to "safety" when using mains-power, although no serious hazards will occur from that.
:headbash:

Christer

15th June 2003 09:22 PM

Quote:

Originally posted by dutch diy Probably each DIY at some point bends one or two rules related to &quot;safety&quot; when using mains-power, although no serious hazards will occur from that.
:headbash:

Most certainly a number of DIYes over the years went listening
to heavenly music sooner than expected because of that. :RIP:

However, it probably will not be a problem for the sound quality
in general, rather, some most likely bend the rules deliberately
for the reason of improving the sound.

pinkmouse

16th June 2003 12:51 AM

Quote:

Originally posted by Christer However, it probably will not be a problem for the sound quality
in general, rather, some most likely bend the rules deliberately
for the reason of improving the sound.

And what is the point in having the most wonderful sounding system, if you, or someone close to you dies because of it...:(

Christer

16th June 2003 01:02 AM

Quote:

Originally posted by pinkmouse

And what is the point in having the most wonderful sounding system, if you, or someone close to you dies because of it...:(

Yes, and that was meant to be implicit in the what I said, in
case somebody missed it.

:att'n: Never compromise safety, especially regarding the mains
voltage circuitry :att'n: (says one who hasn't always lived up
to that in earlier projects, but I do intend on improving in that
respect.)

Actually, this is also an important thing to think about if you
build equpment for friends or sell equipment. It's one thing
if you endanger your own life, but most of us would probably
find it even worse if someone else dies because of an amp
we have designed.

pinkmouse

16th June 2003 01:11 AM

Getting back on topic!

I think one of the things we miss out on is being able to compare different iterations of designs against each other.

I remember Jonathan Carr stating that he would have four or five versions of his products, each with slight changes, on the go at once, so he could check components and layouts very easily for any improvements or degradations. This isn't so practical for the DIYer, unless you're building something cheap and easy like a GainClone.

walker

16th June 2003 05:27 AM

Noisy earths

I have seen a few cases where the amplifier earth was disconnected from the mains earth to cure hum problems; this is of course a dangerous habit.
I had one system brought to me to fix the mains hum. I couldn’t find any problem with the amp and had to travel to the owner’s house to check the installation. I found the main earth connection on the house had been disconnected! Even worse, the connections on all the company owned houses in the street were in the same condition, (we use an MEN, Multiple-Earth-Neutral system here). The local supply authority inspector, a good friend of mine, chased down the cause. A young and over zealous painter had just finished painting all the houses in the street, it was his job to paint the exteriors, the older painters did the insides as they were all air-conditioned. The young painter had disconnected the earth wire from the metal pipe to do a good job. A few of the residents had noticed a tingle when touching the taps but had though no more of it!

If you have a problem with noisy earths get them checked, don’t remove the symptoms, fix the problem before some gets killed. I have even heard of a local salesman suggesting that people cut off earth pins to “fix” the problem, don’t do it!

Having said that, circuit arrangement within the chassis, earthing and cable routes are common reasons why our DIY amps some times play their own tune. I agree with that!